1. Field of the Invention
The present invention relates generally to apparatus for processing wafers, and more particularly to apparatus for gate valve movement in a wet process environment in which a configuration of a wall of a wet processing chamber reduces space available for moving the gate valve to permit wafer transfer to and from the wet process environment.
2. Description of the Related Art
In the semiconductor chip fabrication industry, it is necessary to transfer a wafer (e.g., a semiconductor substrate) into and out of a chamber to facilitate wafer processing operations. For example, for vacuum operations at low process pressures, a chamber may be configured with a flat wall around an opening through which the wafer is transferred into and out of the chamber. In many situations, the flat wall may enable adequate space to be available for gate movement to open and close the opening without interference with wafer transfer equipment.
However, wet processes performed in process chambers may require chamber wall configurations other than the flat configuration, and these wall configurations may present problems in gate movement and wafer transfer. In one wet process example, for reasons of safety and management of wet process materials that may cause contamination outside the chamber, it is necessary to receive and drain (i.e., collect) fluids. The fluids may drip from or flow off a gate as a wafer exits the opening from a wet process chamber. In this example, problems are presented when apparatus for such collecting must be adjacent to an access opening in an otherwise flat wall of a wet process chamber. The collecting apparatus reduces an amount of space otherwise available for gate movement, and there is a problem in satisfying the fluid collecting requirement and at the same time effecting gate movement in the available space without interfering with wafer transfer equipment.
In view of the foregoing, there is a need for improved gate movement in a wet process environment, in which the fluid collecting may still occur adjacent to the opening in a wall of a process chamber while moving the gate relative to the opening to avoid interference with equipment for wafer transfer through the opening.